Fluid catcher for jet pipes



1956 D. R. SWEENEY FLUID CATCHER FOR JET PIPES Filed Dec. 28, 1954INVENTOR.

United States FLUID CATCHER non JET PIPES Donald R. Sweeney, EvergreenPark, Ill., assignor to Askania Regulator Company, Chicago, 1th, acorporation of Illinois Application December 28, 1954, Serial No.478,096

7 Claims. (Cl. 13783) livers a stream of liquid under pressure, usuallyoil, from a discharge orifice, and that is mounted pivotally to swing inresponse to variation of an applied signal, to change the degree ofregistration with the single port, or its relative degrees ofregistration with the two ports, so that the liquid impinging on theport openings develops a pressure that changes in magnitude as afunction of changing jet pipe position. If the jet discharge takes placein air, air is entrained with the jet and injected into the port,upsetting the relationship between pressure and jet pipe position.Additionally, if the discharge is in air, the liquid assumes a turbulentcondition about the port structure, interferes with proper jet deliveryand may affect the position of the jet pipe. Still further, the liquidsplashes against the jet pipe, also affecting its po sition. Assuggested by the identified patent, a liquid catcher corrects theseconditions by enclosing the jet and receiver ports, providing drainageof a character to maintain the enclosed space full of liquid andsufficiently non-turbulent to permit a uniform condition of delivery ofthe jet to the receiver ports by the jet pipe.

The liquid catcher disclosed by the patent is a shell structurestationarily mounted and having an outer tubular side wall thatsurrounds the end portion and discharge orifice of the. jet pipe and thereceiver ports. From an annular rear or outer end wall an inner tubularstructure extends inside the outer side wall toward'the ;receiver port,and the jet pipe extends into the space Eenclosed by the shell throughthis inner tubular strucltllIB which is made as small as permitted bythe necessary swing path of the jet pipe. One or more drainage openingsare provided in the shell for escape of liquid, the total escape pathhaving a cross sectional area so related to the volume rate of liquiddelivery by the jet pipe as to keep the shell filled with liquid, butwith development of minimum back pressure exerted against jet discharge.Liquid also flows through the tubular inner structure about the jetpipe, thereby forming a seal against entry of air through the tubularstructure to the space surrounding the jet and the receiving portstructure.

It is evident that the opening in a liquid catcher shell through whichthe jet pipe extends into the space enclosed by the shell must be largeenough in the directions of the jet pipe swing path to not interferewith movements of the jet pipe. It is also obvious that the narrower thespace filled with liquid to provide a liquid seal against air passage,the more effective the seal will be.

In jet pipe regulators as originally developed, the receiver structurewas stationary and the receiver ports atent were spaced very closely sothat the overall angular dis= tance of jet pipe swinging could belimited sufficiently to make the opening in the inner tubular structureproviding clearance for jet pipe swinging sufficiently small to providea quite effective liquid seal. Subsequent jet pipe regulatordevelopments have provided arrangements wherein the receiver is movablein the directions of the path of swing of the discharge orifice, andthese require clearance openings of increased sizes which, at least incertain cases, permit air to enter the discharge space enclosed by theshell, also provide a path for a liquid flow of sufiicient volume andturbulence to affect the jet pipe position, and to some extent permitsplashing of sufficient violence to upset the jet pipe position.

Another jet pipe development has been arrangement of the receiverelement as a stem-like extension into the jet pipe housing, whichpermits a desirable shortening of the jet pipe, but sometimes results insuch decrease of space available for a liquid catcher as to preclude useof a catcher of the patented type that is of sufficient length toprovide an effective seal against air entry.

The present invention provides a liquid catcher that solves theseproblems, by a novel arrangement for sealing the clearance opening, morepositively and by a physical seal member, but practically withoutpresenting frictional resistance to movements of the jet pipe. The basicconcept of the device is the arrangement of one seal member in closelysurrounding relation to, and for movement with the jet pipe and relativeto a second sealing member provided by the catcher shell wall'structuresurrounding the clearance opening, and closely overlapped by a portionof the first seal member surrounding the area thereof that is registeredwith the opening. The overlapping opposed surfaces are closely spacedand the overlap sufficiently extended to provide an escape pathpresenting substantial resistance to flow of liquid through it, and theliquid that does flow through maintans a floating relation between thesurfaces that practically completely eliminates frictional resistance totheir relative movement. The first seal member, which moves with the jetpipe, may be arranged outside and facing an outward facing wall surfaceof the catcher shell, inside and facing an inner wall surface of theshell, or, preferably, between spaced outward and inward shell wallsurfaces, with opposite surfaces facing both and providing a liquid sealwith each.

In the accompanying drawings:

Fig. 1 is a partial horizontal section through a typical jet piperegulator unit equipped with a liquid catcher arranged according to theinvention.

Fig. 2 is an enlarged fragmentary section on the same plane as Fig. 1,showing the mode of operation of the device.

Fig. 3 is a fragmentary end elevation of the oil catcher of Figs. 1 and2, from the plane of line 3-3 of Fig. 2.

Fig. 4 is a perspective view of the sealing member used in the catcher.

Describing the drawings, and first referring to Fig. 1, the jet piperelay regulator chosen to illustrate the inventioncomprises a jet pipe 5pivoted for swinging in radial fashion about a fixed pivot axis spacedfrom its discharge end 6, in which is an axial end-opening dischargeorifice for delivering a jet of fluid supplied through the interior ofthe pipe. A relay operated by the discharged fiuid jet may comprise theillustrated so-called auxiliary piston which comprises a piston body 7enclosed and axially slidable in a cylinder structure 8, and the pistonmay drive a device such as the illustrated spool type control valve body9. Ports 10, 11 in the ends of piston 7 are connected with a pair ofreceiver ports 12, 13, that are narrowly spaced in the directions ofpiston movement and that are arranged in the end surface 14 of adistributor member 15. In the specific form shown, distributor 15 is astem like member that projects from piston 7 through a clearance opening16 in cylinder structure 8. The invention, however, may be equally wellemployed with an auxiliary piston assembly having the port-carryingdistributor surface 14 flush with the piston side, as shown in UnitedStates Patent to Herbert Ziebolz No. 2,380,357, July 10, 1945, and infact it presents considerable advantage in relays wherein thedistributor is stationary and the distributor ports are connectedthrough passages in stationary structure with opposite ends of acylinder, as shown for example in Patent No. 2,254,098 to the samepatentee. Distributor member 15 has its axis disposed along the plane inwhich the axis of jet pipe moves as the jet pipe is swung, and receiverports 12, 13 also have their axes arranged in that plane. Ports 10, 12and 11, 13 are cross connected in the sense of directions of opening ofports 10, 11 and of directions of spacing of ports 12, 13, by internalpassages 17, 18. By this arrangement, which is well known in jet piperegulators, equal registration between the discharge orifice of jet pipe5 and the two receiver ports results in development of equal pressuresat opposite ends of piston 7, and in a stationary condition of thelatter. When the jet pipe swings to a position of greater and lessregistration with the different receiver ports, correspondingly greaterand lesser pressures are developed at the different ends of the piston,with which respectively the different receiver ports are connected. Dueto the mentioned cross connection, the resulting movement of the pistonis in the direction of the receiver port having greater registrationwith the jet pipe discharge orifice, and it continues until equalregistration is reestablished and the pressures again are balanced. Thuspiston 7 follows swinging movements of the jet pipe dis charge orifice.

The liquid catcher 20 forming the subject of the present inventioncomprises a shell having tubular side wall 21 that is suitably mountedto the cylinder structure 8, as by an end flange 22 secured to a tubularextension 23 of that structure. The catcher 26 has also an end wallstructure provided with a clearance opening through which jet pipe 5extends, so that its discharge end is enclosed by the catcher, and whichforms a part of the novel liquid sealing arrangement provided by theinvention.

One element of the seal, which is carried by and movable with the jetpipe, comprises an annular element 24 having a central opening 25through which the jet pipe is extended and having opposite faces 26, 27at least one of which, and preferably both of which as shown, cooperatewith opposed surfaces of end wall structure of catcher 20. This end wallstructure comprises at least one, and preferably both, as shown, of anend wall 28 having an outer surface 29 that surrounds a clearanceopening 30, and/or an end wall 31 having an inner surface 32 surroundinga clearance opening 33. In the assembly, either or both the face 26 and/or face 27 of annular member 24 overlie the opposed surface 29, 32, ofthe end wall structure, in such spacing asto provide a clearance 34sufiicient to permit member 24 to move with the 'jet pipe, but alsosufficiently narrow'to provide substantial resistance to flow of thefluid. The diameter of member 24 is sutficient as compared to thediameter of the clearance aperture or apertures in the end 'wallstructure withwhich it is cooperative, to insure overlap of the opposedwall structure surfaces and annular member faces sufficient to providethis resistance to fluid flow in all positions of the jet pipe. Adrainage or escape opening 35 is provided in the catcher, preferably inits side wall structure. The cross sectional area of opening 35 is sorelated to the preselected volume rate of jet pipe liquid delivery as toinsure maintenance of the catcher full of liquid and flow of liquidthrough the clearances of the seal, but without development. of backpressure of suflicient magnitude to materially impede liquid jetdelivery by the jet pipe.

Preferably the end wall structure of catcher 20 comprises both an innerwall 28 and an outer wall 31 in axially spaced disposition, and betweenouter and inner surfaces 29, 32 respectively of which the annular member24 is arranged. This not only provides a more extended restricted escapepassage for liquid through clearances 34, but also permits floatingmounting of member 24 on jet pipe 5, by making the diameter of opening25 of the former slightly larger than the outside diameter of the jetpipe, and providing a clearance 36 between the'inner periphery of member24 and the outer surface of the jet pipe.

Advantageously, the end wall 28 is formed integral with sidewall 21,forming a cup-like inner structure, and outer end wall 31 is integralwith a sidewall 37 that is telescopically mounted on side wall 21.Drainage opening 35 preferably opens through both of the telescopedsidewalls 21, 37, and these walls may be relatively rotatable to adjustthe effective cross sectional area of the drainage opening. It may benoted that such an adjustment may be made after the catcher is mountedsince the overlapping type of seal provided by annular member 24 and thecatcher end wall structure requires no rotative orientation between theend wall structure and the plane of swing of the jet pipe axis.

In operation, with jet pipe 5 discharging liquid and the catcher full ofliquid, in addition to escaping through drainage opening 35, the liquidwill flow through the seal clearances as 34 between the opposed faces ofmember 24 and the opposite surfaces of the end wall structure of thecatchec shell, and clearance 36 in the case of the preferred floatingmounting of member 24 on jet pipe 5. This escaping fluid forms filmsbetween the faces 25, 26 of movable member 24 and the opposite fixedsurfaces 29, 32 of the shell end structure, as well as between member 24and jet pipe 5 if clearance 35 is provided in the particularinstallation. These films of moving fluid prevent direct contact betweenrelatively movable surfacesof the seal, and thus prevent frictionalresistance to movement of the jet pipe. This is of extreme importance inrespect to sensitivity of response of the regulator to signal variationsof minute magnitudes. Furthermore, the complete masking of the openingin the end of the catcher shell by the overlapping member 24, and themoving films of escaping fluid, serve completely to eliminate theentrainment of air by the jet, and also completely eliminate irregularsplashing of liquid alongside and into contact with the jet pipe outsidethe catcher shell, as well as surging of escaping liquid through atubular clearance structure through which the jet pipe is extended. Thusthe seal herein disclosed avoids characteristics of previously usedliquid catchers that have in certain instances impaired accuracy of jetpipe regulator operation.

The width of clearances provided in the seal whether between oppositerelatively movable surfaces of member 24 and catcher shell end wallstructure, or between a loosely mounted annular member and the jet pipeit surrounds, as well as degree of overlap of shell end wall structureby the annular member, obviously are not critical. Clearances of theorder of five one-thousandths of an inch in width have provensatisfactory, as well as an annular member diameterof three-quarters ofan inch and diameters of shell end wall openings 30, 33 of onehalf inchhave proven satisfactory in a jet pipe regulator using conventional oiland having a jet pipe orifice swing of the order of one-eighth inch.Such clearances in the specific form illustrated may be providedby'spacing the facing surfaces 29, 32 of end walls 28, 31 at a distancegreater than the thickness of annular member 24 by a distance of theorder of ten one-thousandths inch, and by making the opening of member25 of a diameter greater than the outside diameter of jet pipe 5 by alength of the S me order.

From the foregoing the principles of structural arrangement of oilcatchers embodying the invention, and their mode of operation, will beapparent, and it is to be understood that changes in and modificationsof the exemplary disclosure herein contained may be resorted to withoutdeparting from the invention as defined by the appended claims.

I claim:

1. In a liquid catcher for a jet pipe regulator of the type thatincludes a jet pipe pivoted for swinging and a receiver port-providingstructure facing said jet pipe, and said catcher comprising a shellsidewall structure laterally surrounding said port-providing structurefor enclosing the discharge end of said jet pipe; seal means comprisinga pair of shell walls attached to said sidewall structure and spacedapart to provide opposite spaced surfaces and said walls havingregistered openings smaller than and surrounded by said surfaces, and aseal member of thickness slightly less than the distance spacing saidsurfaces, interposed between the latter and having therein an openingfor penetration by a jet pipe for support of said member by said jetpipe, said opening being located to provide overlapping relation betweensaid member and said surfaces in all positions of said jet pipe.

2. Seal means for a liquid catcher for a jet pipe regulator of the typeincluding a jet pipe having preselected outside cross dimensions andpivoted for swinging and a receiver port-providing structure facing saidjet pipe, and said catcher comprising a shell sidewall structurelaterally surrounding said port-providing structure; said seal meanscomprising a pair of shell walls attached to said sidewall structure andspaced apart to provide opposed spaced surfaces, said walls havingtherethrough re istered openings of dimensions sufiiciently larger thansaid jet pipe cross dimensions to permit such a jet pipe that isextended through them to swing in an arcuate path of preselected length,and said openings being surrounded by said surfaces, and a seal membermovable between said surfaces, said member having a central hole forpenetration of a jet pipe extended through said openings, said memberbeing of a size and having said hole so located as to provide throughoutswing of said jet pipe in said path a substantial area of overlapbetween its different faces and the respective said surfaces, and saidmember being of a thicknes suificiently less than the distance spacingsaid surfaces to permit liquid films to flow between said surfaces andfaces.

3. Seal means according to claim 2, wherein said hole is of dimensionssufficiently larger than said jet pipe outside cross dimensions as toprovide clearance for a flowing film of liquid when penetrated by such ajet pipe.

4. In a jet pipe regulator comprising a jet pipe pivoted for swinging ofits discharge end along a preselected arcuate path, a receiverport-providing structure facing said path, and a liquid catcherincluding sidewall structure laterally surrounding said port-providingstructure and jet pipe discharge end; seal means between said jet pipeand liquid catcher, comprising an end wall attached to said sidewallstructure, disposed transverse to said jet pipe, and having therein aclearance opening of a size and location to provide free clearance forsaid jet pipe in swinging of its discharge end throughout said path, andsaid opening being surrounded by a surface of said end wall, and a sealmember mounted on said jet pipe and having a face opposed to said endwall surface, of a size to overlap said surface throughout said jet pipeswinging, and spaced from said surface a distance to provide for flow ofa thin film of liquid.

5. In a jet pipe regulator comprising a jet pipe pivoted for swinging ofits discharge end along a preselected arcuate path, a receiverport-providing structure facing said path, and a liquid catcherincluding sidewall structure laterally surrounding said port-providingstructure and jet pipe discharge end; seal means between said jet pipeand liquid catcher, comprising an endwall attached to said sidewallstructure, disposed transverse to said jet pipe, and having therein aclearance opening of a size and location to provide free clearance forsaid jet pipe in swinging of its discharge end throughout said path, andsaid opening being surrounded by a surface of said end wall, and a sealmember mounted on said jet pipe inside of said end Wall and having arear face opposed to the inner surface of said wall, of a size tooverlap that said surface throughout the swinging path of said jet pipe,and spaced from said inner end wall surface a distance to provide forflow of a thin film of liquid.

6. In a jet pipe regulator comprising a jet pipe pivoted for swinging ofits discharge end along a preselected arcuate path, a receiverport-providing structure facing said path, and a liquid catcherincluding a sidewall structure laterally surrounding said port-providingstructure and jet pipe discharge end; seal means between said jet pipeand liquid catcher, comprising an end structure including a pair of endwalls attached to said sidewall structure and spaced apart to provide apair of spaced opposite surfaces, and said end walls having registeredopenings surrounded by said surfaces, through which said jet pipe isetxended, and of sizes providing free clearance between said end wallsand jet pipe throughout swinging of the discharge end of the latterthrough said path, and a seal member mounted on surrounding andprojecting radially from said jet pipe between said walls, of a size toprovide substantial areas of overlap of said surfaces surrounding saidopenings throughout swinging of said jet pipe through said path, saidseal member being of a thickness sufiiciently less than the distancespacing said surfaces to provide clearance for a flowing film of liquidbut to present resistance to flow thereof.

7. In a jet pipe regulator comprising a jet pipe pivoted for swinging ofits discharge end along a preselected arcuate path, a receiverport-providing structure facing said path, and a liquid catcherincluding a sidewall structure laterally surrounding said port-providingstructure and jet pipe discharge end; seal means between said jet pipeand liquid catcher comprising an end structure including a pair of endwalls attached to said sidewall structure and spaced apart to provide apair of spaced opposite surfaces, and said end walls having registeredopenings surrounded by said surfaces, through which said jet pipe isextended, and of sizes providing free clearance between said end wallsand jet pipe throughout swinging of the discharge end of the latterthrough said path, and a seal member located between said opposite wallsurfaces, having a hole therethrough penetrated by said jet pipe andsuificiently larger than said jet pipe to provide clearance for aflowing film of liquid through said hole but to present resistancethereto, said seal member surrounding and projecting radially from saidjet pipe, being of a size providing substantial areas of overlap of saidsurfaces surrounding said registered openings throughout swinging ofsaid jet pipe end through said path, and said seal member being of athickness suificiently less than the distance spacing said surfaces toprovide clearance for a flowing film of liquid but to present resistanceto flow thereof.

Wunsch Mar. 15, 1938 Neukirch Ian. 7, 1941

